udp_locator_client.c

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#include "skn_network_helpers.h"


int main(int argc, char *argv[])
{
    char request[SZ_COMM_BUFF];

    memset(request, 0, sizeof(request));
    strcpy(request, "Raspberry Pi where are you?");

    skn_program_name_and_description_set(
            "udp_locator_client",
            "Collect IPv4 Address/Port Service info from all providers."
            );

    /* Parse any command line options,
     * like request string override */
    if (skn_handle_locator_command_line(argc, argv) == EXIT_FAILURE) {
        exit(EXIT_FAILURE);
    }
    if (gd_pch_message != NULL) {
        strncpy(request, gd_pch_message, sizeof(request));
        free(gd_pch_message); // from strdup()
        gd_pch_message = request;
    } else if (argc == 2) {
        strcpy(request, argv[1]);
    }
    skn_logger(SD_DEBUG, "Request Message [%s]", request);

    /* Initialize Signal handler */
    signals_init();

    /* Create local socket for sending requests */
    gd_i_socket = skn_udp_host_create_broadcast_socket(0, 8.0);
    if (gd_i_socket == EXIT_FAILURE) {
        signals_cleanup(gi_exit_flag);
        exit(EXIT_FAILURE);     
    }

    /* Get the ServiceRegistry from Provider
     * - could return null if error */
    PServiceRegistry psr = service_registry_get_via_udp_broadcast(gd_i_socket, request);
    if (psr != NULL && service_registry_entry_count(psr) != 0) {
        char *service_name = "lcd_display_service";

        if (gd_pch_service_name != NULL) {
            service_name = gd_pch_service_name;
        }

        service_registry_list_entries(psr);

        /* find a single entry */
        PRegistryEntry pre = service_registry_find_entry(psr, service_name);
        if (pre != NULL) {
            skn_logger(" ", "\nLCD DisplayService (%s) is located at IPv4: %s:%d\n", pre->name, pre->ip, pre->port);
        }
    }

    /* Cleanup and shutdown
     * - if shutdown was caused by signal handler
     *   then a termination signal will be sent via signal()
     *   otherwise, a normal exit occurs
     */
    if (gd_i_socket) close(gd_i_socket);
    if (psr != NULL) service_registry_destroy(psr);
    signals_cleanup(gi_exit_flag);

    exit(EXIT_SUCCESS);
}